Storing a library on an external drive

You can store an Photos library on an external or removable hard drive just the same as you can on your computer’s built-in hard drive. To create a new library, follow the normal procedure for creating a new library, and choose the external drive as the location for the library. If you have an existing library that you would like to store on your external drive, use the “Duplicate Library” command in the File menu. You will be given a choice of where to duplicate the library to, at which point you can choose the external hard drive that you’d like to copy the library to. Once you’ve created or copied your library on the external drive, you can then open it up just like any other Photos library.

Apple recommends that you store your Photos library on a Mac formatted drive (either MacOS Extended or APFS), and recommends against using SD cards and USB flash drives, as well as network drives. Unless you have a particular need for your external drive to be accessible from a Windows or Linux machine, make sure the disk is formatted as MacOS Extended or APFS, which you can check using the “Get Info” window in the Finder.

For network drives, on macOS Catalina and later a Photos library can be stored on a NAS as long as you’re connecting via the SMB 2/3 protocol, and not Apple’s older AFP protocol which is now deprecated. Photos is not optimized for working over a network, so working with a library there on a day to day basis will likely be slow, and the addition of network access gives one more possible way for data corruption to occur. We recommend working with your libraries on locally attached disks whenever possible and using a NAS primarily for archiving and/or backups. As always, you should make sure you have an additional backup of the library elsewhere as well.

macOS 14 Sonoma There are two issues to be aware of on macOS Sonoma when dealing with some network and external drives.

1. NAS problems on macOS 14.0-14.3 Starting with macOS 14.0, Photos would no longer create or open a library on a network drive, instead displaying an error with the only option being to quit. As of macOS 14.4, this bug appears to be fixed, but proceed with caution if you’re using a library on a NAS on Sonoma.
2. ExFAT problems Also starting with version 14.0, macOS started to have a number of troubles in general with ExFAT formatted drives, including sometimes not being able to mount such drive. In addition, a number of users have reported problems using Photos specifically on ExFAT drives, with Photos producing errors in certain cases when trying to modify the library. Because of these and other issues, it’s highly recommended to only use Mac formatted drives to store your photo libraries, and PowerPhotos will issue a warning specifically when trying to add/create a library on an ExFAT drive.